Justification:
This species is considered to be Least Concern in light of its adaptability to a wide range of human dominated and natural habitats, occurrence in large populations, occurrence in many protected areas, and populations are currently stable. In some portions of the range the species has been increasing for almost a century (especially where large predators have been extirpated) while in other areas populations are small and in decline.

This species occurs from southern Canada south through most of the U.S. and Mexico to South America (Peru, Ecuador, Bolivia, Colombia, northern Brazil, Venezuela, and the Guianas). Southernmost populations in the neotropics may represent other species (Molina and Molinari 1999). Absent from much of southwestern U.S. The species has been introduced in Czechoslovakia, Finland, New Zealand.

Historically probably not as abundant as at the present time in northern populations. Range has expanded northward farther into Canada as a result of habitat changes caused by humans. White-tailed deer population estimated in the United States must be over 11,000,000 of which a third will be in the State of Texas. In Canada the estimation is a half of million deer (Whitehead 1993). Deer herds in Canada and mainly in the United states are overabundant, but in Mexico, Central America and South America most of the populations are declining, and most of the subspecies status are unknown.

White-tailed deer inhabit a wide range of habitats from north temperate to subtropical and semi-arid environments in North America, and include rainforests and other equatorial associations, as deciduous forests and savannas of Central America and Northern South America (Brokx 1984, Danields 1991, Smith 1991). It is abundant in mixed pine-oak forests of Mexico (Ffollott and Gallina 1981), and in second-growth forests and thickets and forest-savanna ecotones of Guatemala, Honduras, Belize, El Salvador, Costa Rica and Panama (Mendez 1984). Ecological limitations in northern or montane habitats are related to depth, quality and duration of snow (Blouch 1984) and in more southern latitudes and lower elevations, the amount and temporal distribution of precipitation (Ffolliott and Gallina 1981, Mendez 1984, Villarreal 1999). O. virginianus favour more mesic climates and vegetation within arid regions. In the Andes countries, distribution of the white-tailed deer is not limited by elevation but rather by steep arid habitat and by rainforest on the mountain slopes (Brokx 1984). White-tailed deer is an extremely adaptable species (see compilation of 500 deer studies in Mexico by Mandujano 2004). The species thrives in close association with man and his agricultural and industrial pursuits. Its requirements are met in practically every ecological type including grasslands, prairies and plains, mountains, hardwoods, coniferous and tropical forests, deserts, and even in woodlots associated with farmland. In the United States, it reaches its largest densities in hardwood forests and bushlands (Teer 1991).

White-tailed deer occupy a well defined home range, but they are not territorial. Home range are influenced by age, sex, density, social interactions, latitude, season and habitat characteristics. Size of home ranges varies inversely with density and vegetative cover. Annual home range averages 59- 520 ha (Marchinton and Hirth 1984). In northeastern Mexico, O. v. texanus home range averages 193 ha for females, and 234 ha for males in a xerophyllous brushland (Bello et al.2004), and O. v. sinaloae in a tropical dry forest in the Pacific Coast of Mexico had a home range of 34 ha during the wet season (Sánchez Rojas et al.1994).

The white-tailed deer is a polytypic species that has become well adapted to different environments. This diversity is reflected in body weight, external dimensions, coat coloration, antler growth and, no doubt assorted physiological, biochemical and behavioural distinctions. In general, the colour is darker in the humid, forested areas, and paler in the drier, more open brushland, reddish in subtropical and tropical environments (Backer 1984). In the northern hemisphere undergo two complete molts per year and exhibit seasonal variation in pelage. The summer coat consists of short, thin, wiry hairs and varies from red-brown to bright tan; the winter coat varies from blue-gray to gray-brown and has longer, thicker and more brittle hairs (Smith 1991). High Andean populations may retain a greyish pelage year-round, while tropical whitetails may keep the tawny,eddish phase (Baker 1984). Adults have a white nose band, orbital region and throat patch. All underparts including lower tail, insides of legs, venter, and chin are white. Fawns have a reddish-brown with white dorsal spots that disappear at 3-4 months of age (Hesselton and Hesselton 1982).

These threats are only considered for the subspecies of Central and South America: feral dogs may be a nuisance to deer in some areas (Causey and Cude 1980). Some populations in Venezuela are threatened by overhunting and habitat loss (Moscarella et al. 2003). Poaching is the other cause of local population extinction.

The main problem in USA and Canada is overabundance, and the consequences are the problems caused to humans, as pests, accidents, and one of the most serious are epidemiology and diseases like Lyme disease and others. So policies are needed to reduce populations. Meanwhile the southern populations have problems to survive and some are threatened by different causes. The species occurs in several protected areas across its range.The populations of Guatemala are listed on CITES Appendix III (as Odocoileus virginianus mayensis).